Idle issues beyond believe

[arabeclipse]

So before I begin, I want to point out that I've read these threads and followed them and not one thing has helped me:

http://www.dsmtuners.com/forums/newbie-forum/385328-idle-surging-problem-help.html

Terry's Talon Troubleshooting Tips #3 - Fast Idle (aka. Idle Surge)

Idle Surge FAQ

http://www.dsmtuners.com/forums/maintenance-repairs/447307-high-idle-surge.html (with this one, I want to determine and confirm the problem before I change anything)

http://www.dsmtuners.com/forums/articles-engine-fuel/191137-how-fix-your-idle-surge-problem.html

http://www.dsmtuners.com/forums/new...rge-problem-cant-figure-out-ive-searched.html

http://www.dsmtuners.com/forums/tuning-engine-management/435139-idle-surge-video-log.html

There's a few more but I can't find them.

So here's the thing. I have an idle surge from 1000-2000rpm. But when I get driving about 10 miles later when I go to shift at any rpm, get off the gas and the engine just revs itself there. So a 3k rpm shift, take my foot off the throttle and the engine continues revving at 3k rpm. And when i go back into gear and take my foot off the gas, it holds the throttle down itself. Bad TPS?

I check the ISC motor. It plunges back and forth like it should. I checked the pins on them too. BUT, pins 4&5 read just over 40 ohms. Everything else is at 30 ohms. Bad ISC?

The throttle cable has some slack in it so it's not causing the high idle.

I did do a BLT. I have a MINISCULE leak at the bov..bad gasket and easy fix. I also cleaned the TB. This issue was going on even before I cleaned the TB. Oh and TB gaskets are fine.

And..the car doesn't have the original throttle body. I don't know where it's from but it doesn't look like its performance oriented. So.. I don't see a BISS. The only screw is the stop screw for the throttle plate that I am positive is adjusted properly.

1995 GST with 3" Gm MAFT and Greddy Type S bov vented, boost controller and boost gauge. Everything else stock.

Thanks everyone! Seriously one of the most frustrating things to deal with next to lifter tick.

 

[92AWDHX40]

Well i would post a picture of the tb.

 

[TSIshwdwn]

Have you tried searching for a vacuum leak because if you already have checked the sensors then that's where I would check next.

I had a massive idle surge before it didnt go away just replacing the ISC valve so I bought another throttle body it's way better now. Not completely fixed but atleast now I can drive it without surging anymore.

Also very important check the sensors i think its engine temperature ( i don't know the name ) but its the one under the thermostat housing, it is on my 6bolt It's worth replacing it just make sure it's working properly.

Goodluck.

 

[curt-s]

Cruise control? Had that problem with sticking throttle on my 1g. Removed CC and all was good.
ISC is a bit out of whack with the resistance, but that could be due to the ohm meter as well. If the contacts aren't totally clean and bare metal which is rarely an occurrence nowadays, a few ohms resistance can be added easily.
Clean everything best you can and try again, even the contacts on the meter. I rotated the plug itself on the meter once about 45 degrees and lowered 3-4ohm resistance in my measurements.

 

[eclipsyco]

Your sensors are good! Even the 40ohms is alright everything above 25 in the isc is ok. The only thing I can think of is vacuum leaks maybe you have a very small crack or something in a hose but only under heavy vacuum it opens example when you let of the gas. Have you tried changing the main vacuum hoses wIth brand new ones?

 

[curt-s]

Even the 40ohms is alright everything above 25 in the isc is ok.

While 40ohms is technically ok, it's dependent on temperature. No, not everything above 25ohm is ok for an ISC -- that's bad information to spread. Especially since a bad ISC can harm your ECU drivers.
Anything out of specification is considered a part failure. ISC coils should be approximately 30ohms when cool and should not exceed 40 if the car is hot.

 

[arabeclipse]

Well i would post a picture of the tb.

It's dark out but i have a previous picture of my engine bay. I zoomed in on the TB for you. I hope this link works:

Essa Hattar's Photos | Facebook

sordid: As for the CC, I checked all the junk in that black box and I did not see any obstructions. And when I checked the ISC, the car was just shut off from a few mile drive. So the engine was warm. I'll clean the contacts for the meter and check again tomorrow. Too dark and raining eclipses and talons outside.

TSIshwdwn: I checked for vacuum/boost leaks and like I said, the only leak I found was the one at the bov. I sprayed down everything and that's all I found. By the way, I only boost 15psi but lately I haven't pushed it passed 10psi...if this info will help at all. I will check the sensor for the engine temperature and let everyone know. I completely forgot to mention that even though I did not find any moderate to major vacuum leaks, my vacuum reads 30.
That's some massive crazy vacuum for no vacuum leaks... even with it being 30 this passed year since I've had it, this idle issue is only a week old.

 

[DSM's 4 life]

I was having issues with my idle as well i boost leak tested and I had a major leak at 15psi at my egr block off plate. The gasket melted but only had 3 miles on it would this cause my idle issues?

 

[Lou98GSX]

i think you should check your tps voltage when you have this problem it should be less than a volt like .63 is good .

 

[arabeclipse]

So I tested the TPS and I'm actually not getting a reading off of pins 2&4. But I am getting about 4000 ohms on pins 1 and 4. I'm confused here.

 

[arabeclipse]

Sorry it's been awhile I've been busy with school.

So I figured out its my throttle body plate. It won't close when the car is on and I can close it manually. I also found that my throttle body is from BBK.

What can I do to keep it from keeping open? Btw my throttle cable has nothing to do with it. I took the cable off and it the TB still stays open until you close it manually.

 

[eclipsyco]

Remove it and clean it with carb cleaner!
If that doesn't help maybe the throttle plate is sitting to tight in there check that out too!

 

[Firsts tuner]

Are the springs installed correctly? Might be a long shot but it's free to look.

 

[arabeclipse]

You guys are quick, thanks.

I already cleaned the SOB and idk why it's still opening. I'm talkin slightly opened here which now I can see translates into a 1500-3000rpm idle, AND surge.

Also I think the spring is weak. Because I noticed that my gas pedal is really light. I heard BBK already gives a lighter pedal feel but something isn't right with it.

Oh I check my TPS and I got it to .626v that's as close as I could get it by hand.

This issue is bugging the living crap outta me. I have this issue and my lower ball joints are about to fall off. Can you imagine both these issues in a parking lot?